Background: shuf is a command that behaves like head and tail, only it returns a selected number random lines. I’m filtering out single quotes (grep -v "'") in its input so as to not unduly annoy xargs, and filtering capital letters (grep -v "[A-Z]") as a proxy for filtering out proper names.

As a note of caution, you don’t want to run rw live in front of other people or send them the output unchecked; a random selection of 2 English words has some reasonable chance of being disgusting, offensive, strange, inappropriate, etc. Generate some memorable phrases privately in advance!